The present invention is concerned with photographic printing systems. In particular, the present invention relates to an improvement which overcomes problems encountered with automatic paper feed systems in photographic printing systems.
Photographic printers produce color or black and white prints from negatives. High intensity light is passed through a negative and imaged on photographic print paper. A photographic emulsion layer on the print paper is exposed and subsequently processed to produce a print of the scene contained in the negative.
Photographic processing centers typically process film from many customers. The printers used in these processing centers must be capable of producing color and black and white prints from a range of negative sizes which include, for example, 110, 120, 126, 35 mm, 70mm and 21/4 .times. 31/4" negative sizes. The desired prints may have ten or more different sizes and may be either with or without a border. In addition, some of the orders call for multiple prints from a single negative.
In order to increase efficiency and minimize the time required to fulfill customer orders, high speed printers in which many exposures are made on a single roll of print paper are desirable. After the many exposures are made, the portion of the roll which has been exposed is removed from the printer, is photo processed to produce prints, and is cut to individual prints. The prints are then sorted by customer order and ultimately packaged and sent to the customer.
One sub-system of a photographic printer which helps increase efficiency is an automatic paper feed system. This automatically advances the print paper by a predetermined feed length after each exposure. The predetermined feed length is determined by the size of the prints then being made and the format of the prints (for example, with or without a border).